IS 14193 : 1994 sre91?r;sc; ( Reaffirmed 2006 ) f=vTFJ VTErZT - fti5lfk Indian Standard OVULATIONTHERMOMETERSSPECIFICATION U D C 615471 : 536*512*083;64 @ BIS 1994 BUREAU OF INDIAN STANDARDS M A N A K B H A V A N , 9 B A H A D U R S H A H Z A F A R MARO NEW DELHI 110002 October 1994 Pdce Group 3 Medical Instruments and Disposables Sectional Committee, MHD 12 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Medical Instruments and Disposables Sectional Committee had been approved by the Medical Equipment and Hospital Planning Division Council. This standard covers the requirements and methods of sampling and test for solid-stem type ovulation thermometers used as an aid to conception or contraceptive purposes. Since these thermometers are used in general for detecting small temperature changes over a period of time, care should be taken to ensure that the sequence of readings is made with the same instrument and using the same procedure throughout. It is therefore recommended that these thermometers be used in conjunction with charts and information available from thermometer manufacturers and local family welfare authorities. This standard keeps in view the related requirements of the Special Schedule: Part II Clinical thermometers `( new part )' of the Manual of Weights and Measures ( vol 1 ), based on the International Recommendation No. 7 Clinical thermometers mercury-in-glass with a maximum indicating device', issued by the International Organization for Legal Metrology ( OIML ). In the preparation of this standard, assistance has been derived from BS 691 : 1987 Solid-stem clinical maximum thermometers ( mercury-in-glass )' issued by the British Standards Institution, UK. For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1960 `Rules for rounding off numerical values ( revised >`. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. IS 14193 : 1994 Indian Standard OVULATION THERMOMETERS SPECIFICATION 1 SCOPE requirements, 1.1 This standard specifies methods of sampling and tests for ovulation thermometers of mercury-in-glass, maximum indicating. solid-stem type, intended for measurement-of deep body- temperature of human beings. 2 REFERENCES 2.1 The following Indian Standards are necessary adjuncts to this standard: IS No. 2303 Title 6 MATERIALS 6.1 Glass 6.1.1 General Requirements The thermometers shall be made` from suitable thermometric glass tubing conforming to IS 4529 : 1968 selected and processed so that the finished thermometers shall have the following charactersistics: a) Stress in the glass of the bulb and stem shall be reduced to a level sufficient to minimize the possibility of fracture as a result of mechanical or thermal shock. b) When tested in accordance with IS 2303 ( Part l/Set 1 ) : 1994, the quantity of alkali obtained in solution from 1 g of the glass shall not exceed 263.5 pg of Na,O. 6.1.2 Glass for the Bulb 6.1.2.1 Zreo point depression Grading glass for alkalinity : ( Part l/Set 1 ) : Part 1 Hydrolytic resistance, Section1 Hydrolytic resistance 1994 of glass grains 90°C - Method of test and classification (first revision ) 2627 : 1963 4529 : 1968 Glossary of terms relating to liquid-in-glass thermometers ( first revision ) tube for medical Glass thermometers Principles of design, construct i o n a n d u s e o f liquid-inglass thermometers 8787 : 1977 When determined by the method given in Annex A, the glass from which the bulb is made shall have a depression of zero not exceeding 0*07"C. The glass shall be identified visibly and indelibly. 6.1.2.2 Stabilization The bulb glass shall be stabilized by a suitable heat treatment. 6.2 Liquid Filling Pure dry mercury shall be used. The mercury, together with the bulb and capillary tube shall be free of gas, glass fragments, foreign bodies and moisture. 3 TERMINOLOGY 3.1 For the purpose of this standard, the definitions given in IS 2627 : 1963 shallapply. 4 TYPE 4.1 Ovulation thermometers shall be of the mecury-in-glass type with a solid stem of `lensfront' section and shall be provided with an enamel aback, 7 SCALE, GRADUATIONS AND DIMENSIONAL REQUIREMENTS 7.1 The scale range shall be between 35 to 38°C and shall include the scale lines at 35°C and 4.2 The thermometers shall be provided with a 38°C. maximum reading device (see 8.2) that prevents the mercury column from falling when the 7.2 The scale length, diameter and other mercury in the bulb returns to the surrounding dimensions of ovulation thermometer shall be in accordance with Table 1. temperature. 7.3 The smallest scale divisions and the linear S TEMPERATURE SCALE scale equivalent ( the distance representing one 5.1 The thermometers shall be graduated in Celsius degree on the scale ) shall be as specified in Table 1. degrees Celsius ( "C ) scale. 1 zs 14193 : 1994 Table 1 Scale and Dimensional k!qUireIUentS for Ovulation Thermometers ( Clauses 7.2 and 7.3 ) Clause 7-3 7.3 Requirement 0.05 8 38°C fo.looC 110 4 15 3.5 to 5.5 55 image of the mercury column shall finish on~a line parallel with the axis of the thermometer. NOTE - It is recommended that those ends of the shortest lines that are closer to the mercury column should not be separated from the nearer edge of the image of the magnified mercury column ( see Fig. 2 ). Smallest scale division OC Linear scale equivalent per OC Min, mm Constriction test temperature, 8.2.1 min Maximum permissible error 9.1 7.2 Overall length, mm Minimum stem diameter, mm 1.2 1.2 Bulb length, mm, M a x ( see Note ) Bulb diameter, mm 7.2 7.2 Scale length mm, Min NOTE - See Fig. 3 of IS 8181 : 1977. 7.4 Marking and Thickness The graduation lines shall be either clearly etched or otherwise durably marked ( see 10 ), shall be of equal and uniform thickness of not more than l/4 of the length of the smallest scale division. 7.5 Length of Graduations T-he graduation lines at 0-5"C and 1°C position shall be longer than those at the smallest scale division. It is recommended that the scale lines at each 1°C and 0*5"C position should be nominally 2 mm in length and that those at the smallest scale division should be nominally 1.5 mm in length. 7.6 Numbering aud Figuring The graduation lines shall be numbered and ~fully figured at each of the temperature positions as indicated in Fig. 1. 7.7 Orientation and Extent The graduation lines shall be at right angles to the axis of the thermometer. One end of each of the longest graduation lines shall extend as closely as praticable to the magnified image of the mercury column. Those ends of the graduation lines that are farther from the magnified 7.8 Numerals When the thermometer is viewed in a horizontal position with the bulb to the viewer's left (see Fig. 1 ), the numerals shall be upright and shall be so placed that they would be bisected by their corresponding scale lines, if these were extended. They shall be either clearly etched or otherwise permanently marked, shall have the nominal height of 2 mm and shall be visible at the same time as the magnified image of the mercury column. 7.9 Locator A locator shall be marked on the stem before the start of the scale to facilitate pnsitioning of the thermometer so that the mercury column is in full view. The locator may comprise a thick dot or line ( 1 mm size or more ) or a rectangle of 1 x 3 mm. 8 MANUFACTURE 8.1 General Requirements 8.1.1 Bulb The bulb shall be cylindrical and shall be ofthe `long' pattern as shown in Fig. 3. The diameter of the bulb shall not exceed that of the stem. The bulb shall be in alignment with the stem. 8.1.2 Freedom from Defects The thermometer shall be free from defects that are likely to interfere with its proper functioning or to mislead the user, including defects in the glass, errors in dividing or figuring, constructional defects or gas trapped in the bulb and/or mercury column. 8.1.3 Surface Condition The surface of the stem and bulb shall be free of cavities that are likely to harbour microbiological contamination. The ends of the thermometer shall be smoothly rounded. . 38 AND 33 / NUMBERING FIG. 1 E XAMPLE OF PREFERRED STYLE OF GRADUATION 2 IS 14193 : 1994 suddenly immersed for 20 s in a vigorousl~y stirred water bath at a constant temperature ( t, ) between 35.5% and 42°C withdrawn and cooled to ambient temperature, the reading: a) shall be within the limits of the maximum permissible error, and F IG. 2 EXAMPLES OF G RADUATION S HOWING THE POSITION OF THE S CALE L INES REI,ATIVE TO THE ENLARGED IMAGE OF THE M ERCURY COLUMN W HERE L IS LESS THAN 0*5T b) shall not differ by more than 0*005 ( I, - t, ) from the stabilized reading for temperature _t,. NOTE - This is a laboratory test and there is no direct relationship to the measuring period in medical use. I2 MARKING SHAPE OF BULB FOR O VULATION THERMOMETER 8.2 Constriction 8.2.1 Temperature Indication There shall be a constriction in the bore below the lowest scale range such that when the thermometer, at ambient temperature, is held in a vertical position with the bulb downwards, after exposure to a temperature of at least 38°C it shall indicate the exposed temperature within the limits of the maximum permissible error specified in 9. 8.2.2 Return of Mercury Column To ensure that the mercury shakes through the constriction without undue effort when the thermometer is being reset, the mercury column shall pass completely -below the lowest scale line when the thermometer is subjected to an acceleration of 600 m/sP at the base of the bulb after heating to a temperature of at least 37°C and returning to normal room temperature. 9 MAXIMUM PERMISSIBLE ERROR 9.1 After immersion in a testing bath at any temperature within the range of the thermometer, followed by return to an ambient temperature of between 15°C and 3O"C, the temperature shown shall be that of the testing bath to within the limits of fO*lO"C!. 10 PERMANENCE OF PIGMENT/MARKING 10.1 The appearance of the scale lines and figuring shall not be significantly affected when the stem of the thermometer is immersed for 20 min, in a 50 g/L aqueous phenol solution at 38°C and then wiped dry. 11 INFLUENCE OF IMMERSION TIME 11.1 When the thermometer, at an ambient temperature ( t, ) of between 15°C and 30°C is 3 FIG. 3 12.1 Each ovulation thermometer shall have the following information marked permanently and legibly on its stem: a) The symbol `"C' near the top of the scale; b) An indication of manufacture; the source of c) A code number to trace the batch of manufacture; d) A recognized mark of the verifying authority showing the year of initial verification; and e) An indication identifying the glass used for the bulb, if the glass is not already identified by its maker. 12.2 Each ovulation thermometer may also be marked with the Standard Mark. 12.2.1 The use of the Standard Mark is governed by the provisions of Bureau of Indian Standards Act, 1986 and the Rules and Regulations made thereunder. The details of conditions under which the licence for the use of Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards. 13 PACKING 13.1 The ovulation thermometers shall be securely packed, individually or collectively, in any manner acceptable to the purchaser so as to minimize the risk of damage in handling, transport and storage. 14 SAMPLING 14.1 Lot All the thermometers of the same type, in ~a single consignment and produced under similar conditions of manufacture shall constitute a lot. IS 14193 : 1994 14.2 For permanence of marking, the number of thermometers to be tested shall depend on the size of the lot and shall be in accordance with Table 2. All the thermometers so tested shall satisfy the test as specified. 14.3 For remaining characteristics given in the specification, all thermometers in the lot shall be tested and shall conform to each of the corresponding requirements. Table 2 Scale of Sampling ( Clause 14.2 ) No. of Thermometers in the Lot Sample Size (No.) 4 leaving the thermometer longer than necessary to reach a maximum temperature but, with too short a time, it will indicate a lower temperature. When the thermometer is used in the mouth, about will probably be 2 min to 4 min sufficient. In high or low ambient air temperature conditions, a thermometer used in the mouth will give a misleading value for deep. body temperature, even after 4 min. This is due to the effect of the external air temperature on the temperature of the tissues of the mouth. up to 500 5 8 13 20 32 501 to 1000 1 001 to 3 000 3 001 to 10 000 10 001 and above 15 ACCOMPANYING SLIP 15.1 Except for those supplied in bulk to hospitals and similar institutions, no ovulation thermometer complying with the requirements of this Indian Standard shall be distributed or sold unless accompanied by a printed slip bearing the manufacturer's name, address and guarantee of accuracy together with the following wording. c) All thermometers specified in this Indian Standard are constructed with a solid stem of `lens-front' section. By slowly rotating the thermometer about its long axis, a position will be obtained where a magnified image of the mercury column is aligned with the scale lines, thus assisting the user to read the temperature or to interpolate between scale lines. d) It should be noted that the value recommended by the Indian Medical Association to represent the `normal deep-body temperature is 37°C. Whilst this value is the generally recognized `normal' temperature it should be emphasized that it is the `average' temperature of deep-body tissues for most healthy people at rest in a neutral temperature environment. e) As these thermometers are used in general " Notes on the use of ovulation thermometers complying with IS 14193 : 1994. a) The time taken for ovulation thermometer to indicate the deep-body temperature depends much more on the patient, or her condition and on the method of using the thermometer than on the thermometer itself. To avoid the danger of misleading the user, therefore, Indian Standard thermometers do not carry any inscription for the time required to take a temperature. No error will be caused by for detecting small temperature changes over a period of time, care should be taken to ensure that the sequence of readings is made with the same instrument and using the same procedure throughout. It is recommended that these thermometers be used in conjunction with charts and information obtainable from thermometer manufacturers and local Family Welfare Authorities. IS 14193 : 1994 ANNEX A ( Clause 6.1.2.1 ) DETERMlNATION OF THE AVERAGE ZERO POINT DEPRESSION to A-2, which have not subsequently been heated A-l CONSl'RUCTION OF TEST above room temperature and carry out the THERMOMETERS following procedure ( see A-3.2 to A-3.5 ) for A-l.1 Using the glass under consideration for each of the thermometers in the batch. the bulb, construct test thermometers with the following specifications: A-3.2 Heat the thermometer to a temperature of 100 f l*O"C, keep it at this temperature for Scale range at least - 3.0% to + 3*O"C; 30 min, remove it from the test bath and allow 0*02"C, 0.05% or Scale interval it to cool to room temperature without the Determine the 0. 1°C; bulb touching any object. correction at a temperature of 0°C within 15 Distance between at least 1.0 mm min of its removal from the test bath and record consecutive scale its value ( K3 ). lines Expansion chamber of sufficient volume for the thermometer to be heated to 400°C without damage Thermometers stabilized ( see A-2 ) A-3.3 Keep the thermometer at a temperature of between 200C and 25°C for seven days, determine the correction at a temperature 0°C and record its value ( K4 ). A-3.4 Repeat the procedure in A-3.2 and determine KS; repeat the procedure in A-3.3 and determine KB; repeat the procedure in A-3.2, and determine &. A-3.5 Further repetitions of the procedure in A-3.3 and A-3.2 may be carried out to obtain corrections up to Kan a,ld Kzn +1, where n ( the number of zero depressions obtained) is greater than 3. A-4 EXPRESSION OF RESULTS A-4.1 Calculate the average depression of zero from the following expression: Stabilization A-2 CONFIRMATION OF STABILIZATION A-2.1 Heat the thermometer in a liquid bath or metal block oven from room temperature to 350 f 10°C and keep it at this temperature for at least 5 min. A-2.2 Cool the thermometer at a rate between 10%/h and 15"C/h to 50°C. A-2.3 Remove the thermometer from the bath or oven, determine the correction at a temperature of 0°C and record its value ( K1 ). A-2.4 Heat the thermometer again to a temperature of 350& lo%, and keep it at this temperature for 24 h. A-2.5 Cool the thermometer as in A-2,2. A-2.6 Redetermine the correction as in A-2.3 and record its value (K, ). A-2.7 lf the difference between Kl and K, exceeds 0*15"C, reject the samples, carry out the stabilization of fresh samples and repeat the procedure in A-2.1 to A-2.6. If the difference between KJ and K, is 0*15"C! or less, carry out the depression of zero test as in A-3. NOTE - The correction mentioned in A-2.3 is the algebraic difference between O'C and the temoerature indicated by the thermometer. mn I c i=m i=li i i i i . . . + t &I - &+I 1 i i (K,-Ka)+(K4-Kj)f(Ks-K,) . . . i where i = number of the test thermometer ; m = total number of test thermometers; and n = number of zero depressions o~btained. A-3 DEPRESSION OF ZERO TEST A-3.1 Select m stabilized test thermometers ( where m is not less than 3 ), tested according A-4.2 If the standard deviation of the mn values of zero depression obtained is less than O.Ol"C, report the average depression of zero as calculated in A-4.1. 5 Bureau of Indian Standards BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 t o promote harmoious development of the activities of standardization, marking and quality certification of goods and attending to connected matters in the country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations. Enquiries relating to copyright be addressed to the Director ( Publications ), BIS. 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